USB: musb: fix CONFIGDATA register read issue

INDEX register has to be set to '0' before reading
CONFIGDATA register which is only present in TI musb
platforms.

Currently the default register access mode is set to
FLAT_MODE thus INDEX register is not getting set
properly with musb_ep_select() which is just a nop
operation in FLAT_MODE.This invalid register read is
causing module reinset failure.

Fixing the issue by moving INDEX register write part to
musb_read_configdata() function itself.
Signed-off-by: Vikram Pandita <vikram.pandita@ti.com>
Signed-off-by: Anand Gadiyar <gadiyar@ti.com>
Signed-off-by: Ajay Kumar Gupta <ajay.gupta@ti.com>
Acked-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

drivers/usb/musb/musb_core.c

@@ -1326,7 +1326,6 @@ static int __init musb_core_init(u16 musb_type, struct musb *musb)
 	int		i;
 
 	/* log core options (read using indexed model) */
-	musb_ep_select(mbase, 0);
 	reg = musb_read_configdata(mbase);
 
 	strcpy(aInfo, (reg & MUSB_CONFIGDATA_UTMIDW) ? "UTMI-16" : "UTMI-8");

drivers/usb/musb/musb_regs.h

@@ -323,6 +323,7 @@ static inline void  musb_write_rxfifoadd(void __iomem *mbase, u16 c_off)
 
 static inline u8 musb_read_configdata(void __iomem *mbase)
 {
+	musb_writeb(mbase, MUSB_INDEX, 0);
 	return musb_readb(mbase, 0x10 + MUSB_CONFIGDATA);
 }